Locking device for throttle valves



April 14, 1931. I M, SLATER 1,800,231

LOCKING DEVICE FOR THROTTLE VALVES Filed April 25, 1930 1L f INVENTOR. I Fm MSlale-z' j/Z/A;

HIS A TTORNE).

Patented Apr. 14, 1931 UNITED STATES PATENT OFFICE FRED M. SLATER, E EASTON, PENNSYLVANIA, ASSIGNOR TO INGERSOLL-RAND COM- IPANY, OF JERSEY CITY, NEW JERSEY, A CORPORATION OF NEW JERSEY LOCKING DEVICE FOR THROTTLE VALVES Application filed April 25,

This invention relates to locking devices, but more particularly to a locking device for throttle valves of the rotary type, such as are usually employed for controlling the admission of pressure fluid into fluid actuated rock drills and similar machines.

' One object of the invention is to assure a broad area of contact between the throttle valve and the means employed for holding the throttle valve in placed position.

Another object is to assure a relatively great resistance to rotation of the throttle valve in the direction of the unintended rotation of such valve due to the vibration of the machine whereon the valve is used.

Other objects will be in part obvious and in part pointed out hereinafter.

In the accompanying drawings illustrating the invention and in which similar reference characters refer to similar parts,

Figure 1 is a longitudinal sectional elevavation of a throttle valve and its casing equipped with the locking device constructed in accordance with the practice of the invention, and

Figure 2 is a side elevation, partly in sec tion, taken trough Figure 1 on the line 2-2 looking in the direction indicated by the arrows.

Referring more particularly to the drawings, A represents a casing, such as may form an integral part of the rock drill or similar machine, which in operation is subjected to terrific vibration. The casing A may accordingly comprise a part of the back head B of a drill which has the usual cylindrical por tion C adapted to extend slidably into the rearward end of the cylinder D. Preferably, a back cylinder washer E is provided which forms a closure for the rearward end of the cylinder D and also serves as a seat for the back head B. The usual side bolts (not shown) may be employed for securing the back head B to the cylinder D.

The casing A is provided with a throttle valve chamber F in which is disposed a throttle valve G. In this instance a recess H is formed at one end of the throttle valvfe chamber F and has a threaded outer end J ccadapted to receive a threaded closure plug 1930. Serial No. 447,283.

K which may serve as a receptacle for a suitable connection L of a hose line for conveying pressure from a source of supply to the recess.

The throttle valve G is of the rotary type. It comprises in this instance a body portion 0 and a reduced stem P at one end of the body portion 0 and having a cylindrical bearing portion Q which extends through an aperture R in the casing A. The throttle valve may be provided at its other end with a flange S adapted to seat against the inner end of the recess II.

As is customary, the stem P may be provided with an outer polygonal portion T for cooperation with a corresponding bore U of a handle V whereby the throttle valve may be manipulated. The means illustrated for locking the handle V on the stem P consists of a pin W which extends transversely through the handle V and engages a notch X in the stem P.

In accordance with the practice of the invention, a substantial part of the polygonal portion T of the stem P is adapted to lie within the aperture R. Preferably, adjacent flat surfaces Y and Z of the portion T are so proportioned and disposed with respect to each other that rotation of the throttle valve G to the extent necessary for carrying the surface Y to the initial position of the surface Z may likewise serve to open or to close the valve. In the drawings the throttle valve is shown in the open position so that a passage 6 formed therein registers with a passage 0 in the casing A whereby pressure fluid may be conveyed to the element intended to be actuated.

Means are provided to engage the flat surfaces Y and Z for holding the throttle valve in placed position. To this end a plunger (Z is disposed slidably in a bore 0 of the casing A which is transverse to the aperture R and communicates therewith. Preferably the bore 6 extends to the inner face of the back head B and is threaded as at g to receive a closure plug 72,. The plug 71. is thus adapted to seat against the back cylinder washer E to assure its retention in the bore e.

The plunger (Z is preferably provided with a flat surface j at one end to engage the fiat surfaces Y and Z. A spring is disposed in the bore 6 and acts against the plunger 0Z to force the surface into frictional engagement with the surfaces Y and Z.

In order that a relatively greater resistance may be encountered in the rotation of the throttle valve G from the opened to the closed position, the bore 6 may be offset with respect to the longitudinal axis of the aperture R in the direction of the line of travel of the throttle valve for closing the said valve. The surface j of the plungerd is accordingly inclined to present a broad area of contact to the surfaces Y and Z.

In the drawings, the plunger 03 is shown engaging the surface Y in the open position of the throttle valve G and rotation of the 1 throttle valve tov the left will effect the closing of the valve and bring the surface Z in contact with the plunger (Z. The force applied for closing the valve, in this instance, acts against the plunger (Z in the direction approaching a right angle to the longitudinal aXis of the plunger and there fore occasions considerable friction between the plunger (Z and the side of the bore 6. Conversely, as thethrottle valve is being rotated from the closed position to the open position, the force applied for depressing the plunger (Z acts in'a direction approaching the longitudinal axis of the plunger sothat the re-' sistance encountered is little more than the spring pressure. This is desirable since the throttle valve may be effectively prevented from accidently closing and yet be readily opened.

Inthe present instance means are provided to positively limit rotation of the valve to movement between the positions in which the plunger (Z engages the surfaces Y and Z of the stem P. Accordingly, the casing A may be provided with an arcuate groove 1) adjacent the outer end of the aperture R which is adapted to receive a tang 0 carried by the handle V. The groove p is of such length thatv in the closed and open positions of the throttle valve G the tang 0 may abut the opposite end walls of the groove, and

thereby limit the rotation of the valve.

I claim:

1. In a locking device, the combination of a casing having a valve chamber and a throttle valve rotatable in the valve chamber, flat surfaces on the throttle valve, a

bore in the casing transverse to the valve chamber andv offset with respect to'the longi-' tudinal axis thereof, and means slidable in .the bore to engage the fiat surfaces for affording greater resistance to rotation of the throttle valve in one direction than in another direction. p

a locking device, the combination of a casing having a valve chamber and a throttle valve rotatable in the .valve chamber, surfaces on the throttle valve arranged angularly with respect to each other to cor respond to the angle of rotation of the throttle valve for opening and closing said valve, a bore in the casing transverse to the Valve chamber and offset with respect to the longitudinal axis thereof, and a plunger slidable in the bore to engage the surfaces for afior'ding greater resistance to the rotation of the throttle valve toward the closed position than toward the open position.

3. In a locking device, the combination of a casing forming a valve chamber and a throttle valve rotatable in the valve chamber, surfaces on the throttle valve arranged a-ngul'arly with respect to each other, said casin having a bore transverse to the valve chain er and ofiset with respect to the longitudinal axis of the valve chamber, a spring pressed plunger in the bore, and an inclined surface on the plunger to engage the surfaces for holding the throttle valve in the closed and open position. p

4. In a locking device, the combination of a casing having a valve chamber. and. a throttle valve rotatable in the valve chamber, an opening in the casing opening from an end of the valve chamber,a stem on the throttle valve extending into the aaerture and having a polygonal portion, acjacent flat surfaces of said polygonal portion being arranged angularly with respect to each other to correspond to the angle of rotation of the throttle valve for opening the said valve, a bore in the casing transverse to the aperture and offset with respect to the longitudinal axis thereof, and a springpressed plunger in the bore having an inclined surface to engage the flat surfaces and affording greater resistance to rotation of the throttle valve toward the closedposition than toward the open position. I

In testimony whereof I have signed this specification. V, p

FRED M SLATER. 

